The present invention relates to a camera equipped with flash unit, particularly to a zoom lens camera equipped with a zoom lens and an electronic flash unit which can automatically control its illuminating angle in accordance with the adjustment of the magnification of a zoom lens. The zoom lens camera, when combined with a light-sensing device, can adjust a light-sensing angle as well.
Generally, in taking a photograph of an object by using a zoom lens, its magnification is changed by changing its focal distance. This results that the angle of view for the object to be photographed changes with the magnification. In the case of supplying an artificial illumination by an electronic flash unit for photographing with such a lens system, the illuminating angle of the electronic flash unit should be made to be adjusted to correspond to the minimum focal distance of the zoom lens to be used so as it may cover all angles of view dependent on the change of the magnification.
The illuminating angle corresponding to the minimum focal distance results in the widest illuminating angle of the electronic flash unit. Now, if the electronic flash unit that has been set for the minimum focal distance of the zoom lens is used with the magnification changes by setting a focal distance longer than the minimum focal distance, only a part of the light is directed for the illumination of an object to be photographed, since the angle of view for the object is now smaller, resulting in an inefficient use of the flash light.
A distance possible to illuminate an object with an electronic flash unit set at the widest illuminating angle, is limited. It may be preferable that the electronic flash unit can direct an intensive light as far as possible. This is desirable in the case of a camera having a zoom lens, since the latter is to photograph an enlarged view of a far away object.
Electronic flash units are known which can sense the light reflected from an object with a lighsensing element and can cease providing illuminating light when the quantity of the light sensed reaches a predetermined value. In order to combine this kind of electronic flash unit with the above-mentioned zoom photo camera, a light-sensing angle sensed by the light-sensing portion should be also made variable in accordance with a change in the magnification of the zoom lens for taking a photograph of an object at a long distance.
Because angles of view for an object are changed with the magnification of the zoom lens being changed, the light-sensing element will not sense the light reflected only from the object in the angle of view, if its light-sensing angle is fixed. Therefore it cannot sense the reflected light correctly and therefore cannot correctly control the quantity of flash light.